Stone wrote:A power amp to match the SMS pre-amp would most certainly put me over the edge!

I thought so too then realized I'd likely be the only one on this forum who'd want EL84s

Ok Brad, you are hearing the product development team here, we want a power amp that has switch voicing and can use any power tube we choose to put in the socket.

That concept is do-able. I had a Groove Tubes Soul-O 75 head at one point. It was basically most of a Trio preamp (Clean and Scream) with a 75-watt power amp section with a specially designed Mercury Magnetics transformer that would allow you to run any power tubes you wanted (6L6, EL84, etc.) and decide if you wanted to run Class A, Class AB or Class A pushed (like a vintage Vox). You could also vary the ohms for your speaker cabinet. The cabinet itself had a removable panel on the back so it could be open back or closed. Very versatile amp and a lot of studio players back in the day coveted them for that flexibility.

Just picked up a 75 watt stereo (75 on each side) SS power amp at my trusted Guitar Pawn Shop. It's a Legion Sound 2U Power amp. Sounds great! I used it with my Gr-20 Synth and I am finally happy with it. The MIDI sounded terrible through the tube preamp and amp. Going to run each channel to it's own JBL E120. Can't wait! So, I finally bought the sms classic preamp. All I was looking for was a clean fender-like rack preamp, and the JG mods are a bonus. I know I won't regret it. I'm sure all of you are happy I finally pulled the trigger on a ss power amp. Found everything I was looking for, so no more annoying threads! Thanks guys!

I have another Tech Question about the SMS... The tone stack behaves like a Fender Twin does correct? by changing the treble there is a shift in the midrange dip? I was reading the product manual and it mentioned this: (From the SMS Product manual):

TREBLE - Yup, it controls the amount of treble.

MID - The midrange control on this preamp is a cut-only function. Cranking the "MID" knob willapproach a flat response but never boost mids. The voicing of this preamp will always tend to havesome degree of midrange dip, just like any classic guitar amp. Mid settings below 12-noon willhave subtler changes in the sound compared to settings past noon.

BASS - You guessed it. This knob controls the amount of bass frequencies in the sound.

REVERB - This knob controls the amount of reverb that gets blended in. The internal reverb is ahigh quality 24bit "hall" type that has a realistic and natural sound that blends well with just aboutanything

I assume it functions like a normal twin...

Also, Would this preamp work well as a DI box for an acoustic instrument? I noticed he mentioned the use of the Dark switch in this matter if going direct will shave off the tweetery highs associated with direct connections. Was wondering if any of you acoustic guys have used it as an acoustic rig too and how it is working out compared to a Fishman DI or the like...

mijknahs wrote:I don't think the preamp of a Twin (SMS) is a preamp of choice for acoustic instruments.

I was just wondering. I saw Warren Haynes recently plug into a twin with an acoustic and he had a great sound. Although you are right most people opt for other acoustic styled preamps, but the modern plastic acoustic tone sucks to me IMO with all that verb/echo/chorus/compression layered in. I guess it is fine, but it doesn't sound like an acoustic guitar to me, more like a processed electric. I have been experimenting with using a clean guitar amp like a twin to amplify the acoustic and it sounds more like an acoustic to me. I like to also use a parametric EQ and some effects to clean out the mud, but the sound is not as brittle as the "acoustic processors" direct to the board. I have played through those a bunch too. It's like the notes lack authority or something. To each his own I guess...

Acoustic guitar pickups LOVE tubes in a big big way, but I've found that they don't generally like the EQ voicing in a Fender amp. Seems better to use some type of flat response tube buffer, and then use a flat response EQ/preamp to tailor the high/low balance, maybe notch out that mid-bass feedback frequency, and then maybe work with a possible barky midrange factor. Acoustic preamps are good about addressing those EQ needs, but most of them sound like crap without the help of a tube somewhere because piezo pickups only become more harsh and plasticky sounding going into transistor devices. The signal from a piezo pickup is wildly unwieldy, the output impedance from a piezo is a very inconsistent and unstable thing, and that's why so often amplified acoustic guitars have that gritty, glassy, harsh haze that irritates the ears and veils the natural guitar sound. And especially with hard strummers. Tubes by their very own nature can handle this fluctuating signal from a piezo far better than FET's or other transistors. A passive piezo pickup directly into a tube sounds more like a microphone that many would believe. The tube's ability to track that signal actually gives a much cleaner and lower distortion sound than solid state devices. That crispy harshness we hear from amplified acoustic guitars is basically distortion. Tubes remove much of that stuff and you're left with a surprisingly natural, wood and string sound. Still kind of weird because the pickup is located at one place on the guitar unlike a mic out front that sees the whole instrument, but the tone character thru the tube is SO much more pleasant than with a transistor.

Even if a guitar has active electronics in it, a tube immediately after that stage helps tremendously because that crazy, spiky, high frequency garbage only generates more and more distortion as it passes thru consecutive transistors stages. If a tube is right there early in the path, the whole sound is sweetened and cleaned up, and then any following transistor preamp stages are able to simply EQ and drive without adding more harshness.

I've definitely tried using the SMS or similar tube circuits for acoustic guitars and the result was just kind of weird. The tube factor is nice, the but tone shaping is wrong. The Fender EQ is far from flat and to me is really for electric basses, steel guitars and electric guitars. Oh, and Rhodes pianos too.

Sm81's are real nice, a classic standard for sure. There are a number of sweet sounding pencil condensers, Neumans (KM84 yeah!!!) , AKG's (c451!!), AT's, and more. The obvious problem is feedback. You can only get so loud with a mic before feedback kicks in. I think that's why the acoustic world has gone DI for the most part.

One traditional trick that's been a pro standard approach since the '70s is to use a mic and a piezo pickup together. Since the mic will feed back in the bass frequencies first, they'll roll all the lows out of the mic to prevent that feedback and let the mic capture the natural treble. Then since the piezo pickups sound so shitty and abrasive they'll roll all the highs out of that channel and only use the pickup for the lower stuff. Then at the mixer those two are blended to make a complete sound. I'm not sure, but I'd bet that the Dead's Rekoning album from '80 was done with this method as it was pretty standard procedure in the biz and they have a pretty nice and natural acoustic sound there.

SarnoMusicSolutions wrote:Sm81's are real nice, a classic standard for sure. There are a number of sweet sounding pencil condensers, Neumans (KM84 yeah!!!) , AKG's (c451!!), AT's, and more. The obvious problem is feedback. You can only get so loud with a mic before feedback kicks in. I think that's why the acoustic world has gone DI for the most part.

One traditional trick that's been a pro standard approach since the '70s is to use a mic and a piezo pickup together. Since the mic will feed back in the bass frequencies first, they'll roll all the lows out of the mic to prevent that feedback and let the mic capture the natural treble. Then since the piezo pickups sound so shitty and abrasive they'll roll all the highs out of that channel and only use the pickup for the lower stuff. Then at the mixer those two are blended to make a complete sound. I'm not sure, but I'd bet that the Dead's Rekoning album from '80 was done with this method as it was pretty standard procedure in the biz and they have a pretty nice and natural acoustic sound there.

B

I'd get a AKG 451 if I could afford it. I think that's Tony Rice's mic of choice and he only uses mics alone (no onboard electronics).

SarnoMusicSolutions wrote: Seems better to use some type of flat response tube buffer, and then use a flat response EQ/preamp to tailor the high/low balance, maybe notch out that mid-bass feedback frequency, and then maybe work with a possible barky midrange factor.

Brad

So a Di box that is tube driven or maybe a tube buffer like SGBB going direct to a board. The SGBB sounds like it would be perfect for what you are talking about. How about running it through a regular IC based buffer into a tube DI box?